Abstract: A constant input impedance AC coupling circuit for a current probe measurement system has a resistive-capacitive network that includes a capacitor for coupling the current output signal of a current measurement probe to the low input impedance measurement instrument and the resistive terminating element disposed in the measurement instrument. The resistive-inductive network includes a resistor and a synthesized inductor having a high inductive value, large current carrying capacity and an L/R time constant equal to the RC time constant of the resistive capacitive network. The resistive-inductive network is coupled to the resistive-capacitive network and receives the current output signal from the current measurement probe for terminating DC and low frequency signal components of the current output signal below the low frequency cutoff of the resistive-capacitive network in the same low input impedance of the measurement instrument.

Abstract: A butt joined electronic assembly has first and second coplanar transmission structures that are independently aligned in a proximate abutting relationship. The coplanar transmission structures are formed on at least a first standoff dielectric substrate and on first and second electrical elements. The standoff dielectric substrate is positioned in an abutting relationship with one of the electrical elements. The standoff dielectric substrate and the first and second electrical elements are secured on respective independently positioned and mechanically joined first and second open end face carriers. The first and second coplanar transmission structures are electrically coupled together via substantially flat electrical conductors.

Abstract: A measurement test instrument voltage management system for an accessory device has a accessory device interface that provides a voltage to a memory device in the accessory device. A sensing signal is generated when the accessory device is connected to the interface that causes an interrupt signal to be coupled to a controller. The controller retrieves accessory device data stored in the device memory via the interface and determines if the connected accessory device is a valid device capable of being supported by the measurement test instrument and voltage power requirements for the accessory device. The controller generates an enable signal for a valid and supported device that is coupled to a voltage switching circuit. The voltage switching circuit generates at least a first output voltage based on the voltage power requirements that is coupled to the accessory device via the interface to provide power to the accessory device.

Abstract: A current probe transformer temperature monitoring method determines an initial transformer temperature of the current probe as a function of the winding resistance of the transformer. A relative temperature of the Hall Effect device is also determined as a function of resistance change of the Hall Effect device. The initial transformer temperature and the relative Hall Effect device temperature are combined to produce a continuous transformer temperature indicative of the temperature of the transformer. The current signal to the multi-turn winding is removed when the continuous transformer temperature exceeds a threshold temperature value and a visual indication may be provided.

Abstract: A method and apparatus for calibrating at least signal probes associated with a signal analysis device by storing existing input channel parameters, performing appropriate calibration procedures and restoring input channel operational parameters.

Abstract: A multi-channel, low input capacitance signal probe head has a housing that receives one or more substrates having input signal pads exposed on one end of the substrate. The substrate is positioned in the housing such that the signal contact pads are exposed at an open end of the housing. A removable signal contact holder mounts to the housing and supporting electrically conductive elastomer signal contacts. The holder is disposed over an open end of housing such that the elastomer signal contacts engage the input signal pads. A probe head retention member is provided for securing the multi-channel signal probe head to a device under test.

Abstract: An electrical probe for a flying leadset of a logic analyzer probe has coaxially aligned internal elements enclosed in an insulating cover. The probe has an electrically conductive contact having contact fingers extending in one direction from a support member and a contact member extending in the opposite direction. A sleeve abuts the contact member and receive a center conductor of a conductive cable that is secured in the contact member. The insulating cover has a contact cover portion and a over-mold portion that are chemically bonded together. The contact fingers are positioned in the contact cover and the over-mold portion encapsulates the rest of the probe. The contact fingers are aligned parallel with one side of a square aperture formed in the contact cover. A resistive element may be interposed between the contact member and the sleeve.

Abstract: An adjustable delay line phase shifter is configured as a microstrip transmission line having a M×N matrix of conductive elements mounted on a insulating substrate. The squares are connected together using conductive members, such as gold ribbon or wire bonds, in a pattern that produces a desired amount of phase shift.

Abstract: A measurement probe has housing in which are disposed a spring loaded coaxial probe assembly and a pressure sensor. The probe assembly is formed from a semi-rigid coaxial cable having a probing tip formed at one end and a coaxial connector at the other end. The pressure sensor has first electrically conductive contact secured and electrically coupled to the semi-rigid coaxial cable and a second electrically conductive contact positioned and secured within the internal cavity of the housing. The probing tip is coupled to electrical ground via a control module when the housing is in a first position and the probing tip is coupled to the input circuitry of the measurement test instrument via the control module in response to an activation signal generated by the pressure sensor in response to movement of the housing to a second position and coupled to the control module.

Abstract: A measurement probing system has a measurement probe having a housing, spring loaded coaxial probe assembly and a pressure sensor that generates a resistive activation signal in response to movement of the housing in relation to the spring loaded coaxial probe assembly. The activation signal is applied to control circuitry in a control module for generating an output signal to drive an RF relay to couple the probing tip of the measurement probe from electrical to input circuitry of a measurement test instrument. The control circuitry further includes a TTL buffer circuit for generating the output signal in response to a TTL logic signal from a controller for automated testing of a device under test.

Abstract: Initial mask and waveform positions on a display screen may be determined by an AUTOSET TO MASK function. Upon detection of violations that occur after the AUTOSET TO MASK function is complete, control for further alignment of the waveform under test and the mask is assumed by an AUTOFIT TO MASK function. Comparison of the mask pixels and waveform pixels to detect collision between a waveform pixel and a mask pixel (i.e., a mask violation) is performed substantially in real time, as the pixels are being composited into the raster memory by the rasterizer. In the event of a mask violation, a mask violation signal is generated. In a further embodiment of the invention, in response to the mask violation signal, the AUTOFIT TO MASK function uses display rasterization to automatically redraw the waveform at a new location, until the waveform fits within the mask.

Abstract: A butt joined electrical apparatus has an open end face carrier or housing on which is positioned an electrical element. An electrical device and a coplanar transmission structure is formed on the electrical element with the coplanar transmission structure disposed toward the open end face of the carrier or housing. The electrical device coupled an electrical signal to and from a mating opto-electrical apparatus or housing. The coplanar transmission structure is independently aligned in three mutually perpendicular directions and in a proximate abutting relationship with another matching coplanar transmission structure formed on an opto-electrical element of the mating opto-electrical apparatus or housing. The electrical and opto-electrical apparatuses are independently positioned and mechanically joined together with the matching coplanar transmission structures electrically coupled together via substantially flat electrical conductors.

Abstract: A butt joined opto-electrical apparatus has an open end face carrier or housing on which is positioned an opto-electrical element. An opto-electrical device and a coplanar transmission structure is formed on the opto-electrical element with the coplanar transmission structure disposed toward the open end face of the carrier or housing. The opto-electrical device is coupled to receive and optical signal from an optical waveguide. The coplanar transmission structure is independently aligned in three mutually perpendicular directions and in a proximate abutting relationship with another matching coplanar transmission structure formed on an electrical element of a mating electrical apparatus or housing. The opto-electrical and electrical apparatus are independently positioned and mechanically joined together with the matching coplanar transmission structures electrically coupled together via substantially flat electrical conductors.

Abstract: The invention involves storing information about the probe frequency response in the probe itself. The information preferably consists of a set of one or more characteristic frequency response data points. Each data point includes at least the gain of the probe at a given frequency. More preferably, each data point includes the complex transfer characteristic of a probe (S21 in FIG. 2) and optionally the complex output reflectivity of the probe (S22 in FIG. 2) and the frequency (F in FIG. 2) at which the data applies. A variable number of frequency points can be stored, as necessary, to adequately describe the probe's response. The probe also preferably stores a header containing the number of stored data points. The invention readily extends to probes having multiple gain settings or multiple bandwidth settings, by simply storing multiple sets of S21, S22 and F data.

Abstract: An electronic instrument with a housing in the form of a rectangular body. The housing has a front panel with a display screen, and opposed side panels extending perpendicularly from the front panel to a rear panel. The housing defines a cavity adjacent to the rear panel and at least one of the side panels. The cavity includes a recessed panel portion having attached electronic connectors, so that cables connected to the connectors can flex to avoid protruding from the side panel to facilitate rack mounting, and may extend without protruding from the rear panel for bench usage. A circuit board to which the connectors and a microprocessor are connected may be oriented parallel to the rear panel, allowing a limited front-to-rear depth for the housing.